PDA

View Full Version : 8 ohm tweets and 4ohm crossover



BLD 25
02-03-2008, 09:43 PM
Just curious as to what happens when you use 8 ohm tweets with a crossover made for 4 ohm tweets. There are many good inexpensive tweeters that are fun to mess with from partsexpress.com, but very few passive 8 ohm crossovers. I don't want to go active just yet, but maybe this summer when i have more time.

I am pretty sure that the xover point is cut in half, but what else happens? Anything?

thanks

tcguy85
02-03-2008, 11:24 PM
yea it messes with the crossover point, other than that i'm not sure what else it does.

JimJ
02-03-2008, 11:25 PM
but very few passive 8 ohm crossovers.

Because using pre-built generic crossovers is baaaaaaaad.

tcguy85
02-04-2008, 12:14 AM
Because using pre-built generic crossovers is baaaaaaaad.

yea, go active. it's not really that hard.

Techchild
02-04-2008, 12:19 AM
yea, go active. it's not really that hard.

not trying to threadjack but is it possible to go active without a headunit that has that feature?

JimJ
02-04-2008, 12:22 AM
Yes, you'd need an external crossover, or amps that have crossovers built in to them. But I've never really been a fan of amp-mounted crossovers...

tcguy85
02-04-2008, 12:23 AM
not trying to threadjack but is it possible to go active without a headunit that has that feature?

yup sure is. there are amps with built in crossovers and there are external crossovers that can be used. it's much simpler when it's right in front of you though right in the HU.

EDIT: beat me to it!

Techchild
02-04-2008, 12:23 AM
Yes, you'd need an external crossover, or amps that have crossovers built in to them. But I've never really been a fan of amp-mounted crossovers...

how much do those normally cost external crossovers?

tcguy85
02-04-2008, 12:24 AM
But I've never really been a fan of amp-mounted crossovers...

why is that? just curious.

JimJ
02-04-2008, 12:27 AM
Usually they're limited in the slope, and the crossover point itself...better than a fixed passive for sure, but unless you happen to get very lucky you're not going to be able to dial in exactly what your setup needs.


how much do those normally cost external crossovers?

$50-200ish, depending on what you want done...

tcguy85
02-04-2008, 12:51 AM
Usually they're limited in the slope, and the crossover point itself...better than a fixed passive for sure, but unless you happen to get very lucky you're not going to be able to dial in exactly what your setup needs.


ok makes sense.

BLD 25
02-04-2008, 07:45 AM
10 replies, and not one helpful answer. completely threadjacked. Look, i said i would go active later, but i just want to mess around with a couple of inexpensive setups for fun.

BLD 25
02-04-2008, 09:08 AM
not trying to threadjack but is it possible to go active without a headunit that has that feature?

thread jacked

azngotskills
02-05-2008, 11:25 PM
I the HP xover point would be lowered if you had a passive for a 4ohm tweeter but using a 8ohm tweeter instead :)

tcguy85
02-05-2008, 11:35 PM
I the HP xover point would be lowered if you had a passive for a 4ohm tweeter but using a 8ohm tweeter instead :)

yes and this WAS stated before this thread was jacked.;)

azngotskills
02-05-2008, 11:52 PM
yes and this WAS stated before this thread was jacked.;)

Quote where is said that? All i see is "it will get messed up" ;) and "go active, its easier" :rolleyes: etc... hahaha :D

What exactly are you trying to run together? What crossovers? Im just curious and i may be able to try to help you...

tcguy85
02-05-2008, 11:57 PM
yea it messes with the crossover point, other than that i'm not sure what else it does.

this.... the 2nd post. i couldn't remember if it raised the point or lowered the point so i just simply said it messes with the crossover point.

i should have been more specific but i couldn't remember which way it moved the crossover. sorry

azngotskills
02-05-2008, 11:59 PM
I was just messing with you man :D

tcguy85
02-06-2008, 12:04 AM
I was just messing with you man :D

it's kool! :cool:

BLD 25
02-06-2008, 09:07 AM
yes and this WAS stated before this thread was jacked.;)

actually, that was stated by me. The only positive statement was "i know it messes with it somehow, but i don't know how."

BLD 25
02-06-2008, 09:12 AM
thanks mark. I have just been messing around with different inexpensive setups for a backup car, wife's car, and brother in law's car. I got some of the new nd28 tweets from PE:

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=275-040

I wanted to see if i could get them to work with some passive crossovers that xover at:

1. 4200hz
2. 3500hz

If not, i have some JL passive xovers that cross at 5000hz but are made for an 8ohm tweet. I just hate not using that other 3000hz that is available on the nd28.

I will go active someday, but now, i am messing with passive. If they just cut in half, then the 4200hz xover would be perfect, and i would have a little overlap with the tweeter and woofer.

JimJ
02-06-2008, 10:53 AM
10 replies, and not one helpful answer.

I tried to be nice.

Basically, it's going to ****.

But if SQ isn't all that important...go for it.

BLD 25
02-06-2008, 10:57 AM
thanks Jim! You are so constructive! i am not competing here folks, i have a nice system in my car, i just want to mess around with some stuff. Jeez.

Mr T
02-06-2008, 02:08 PM
Going active can cost about the same as going passive if you already have a 4 channel laying around...

Coustic XM6 for ~50 bucks, you can't really go wrong...